In classical film cameras the user can recognize the operation of the camera by hearing a shutter sound. In many digital cameras there is no mechanical sound when taking pictures. Therefore in some digital camera applications a shutter sound is generated by a separate sound source when an image is captured.
Usually digital cameras comprise some kind of a user interface (UI) that comprises said sound source and a display. In the display it is possible to show a great deal of information. This information can relate to the functions of the camera, for example to the memory or to the settings for image quality. Digital cameras often contain several settings for image quality. Through the settings a user can control the resolution and compression level of the final image.
In practice the user often takes pictures in a situation, where all attention is required. The user is not able to look at the display of the device. The display may also be turned off or the user interface elements may be hidden, so the information of the functions of the camera cannot be displayed. The settings may be different than the user would prefer in this situation, which may cause a negative user experience.
If the user is taking pictures with a digital camera without looking into the display or by using a mode where the image quality setting indication is not visible, the user may continue shooting pictures with the wrong settings for a long period of time. A similar problem exists if the user is taking pictures with a digital camera without looking into the display or by using a mode where memory indication is not visible; the user is not aware of running out of memory while shooting pictures.
Therefore in some digital cameras warning tones (or sounds) are used, such as beeps, to note that there may be some problems in the operation of the camera. For example the memory is running out, the battery is almost empty, or some settings are wrong.